Medical device balloons containing thermoplastic elastomers

Abstract

A dilatation balloon and catheter for insertion into a bodily conduit. The catheter (10) includes shaft (12) and a dilatation balloon (24) at the distal end of the shaft. The balloon is inflated via a central lumen (14) in the shaft for delivery of a fluid inflation media. The balloon is fabricated from a combination of a thermoplastic elastomer (TPE), preferably an engineering thermoplastic elastomer (ETE), with a non-compliant structural polymeric material. The combination may be a blend of the non-compliant structural polymer and the TPE. Alternatively, the combination may be a layered balloon having, for example, a non-compliant structural polymer inner layer and a soft, abrasion resistant, elastomeric outer layer. Methods for fabricating the balloon from the combination of a TPE and a non-compliant structural polymer are also disclosed.

We claim: 
     
       1. A dilatation balloon for use in a medical device, the balloon having a structural layer which is a blend consisting essentially of polyethylene terephthalate (PET) as its major component and as a minor component a randomized block copolymer of polyether glycol and polybutylene terephthalate. 
     
     
       2. The balloon of claim 1 further comprising an elastomeric layer outside of the structural layer. 
     
     
       3. The balloon of claim 2 in which the elastomeric layer comprises a blend of an ETE with PET. 
     
     
       4. A dilatation balloon for use in a medical device, the balloon comprising a structural layer which is a blend consisting essentially of polyethylene terephthalate (PET) as its major component and as a minor component a randomized block copolymer of polyether glycol and polybutylene terephthalate, the balloon further comprising an elastomeric layer outside of the structural layer, said balloon being made by a process which comprises coextruding the elastomeric layer and the structural layer. 
     
     
       5. A dilatation balloon for use in a medical device, the balloon having a structural layer which is a blend comprising at least two components: a) polyethylene terephthalate (PET) as its major component; and b) as a minor component a randomized block copolymer of polyether glycol and polybutylene terephthalate, said blend components not being covalently bound to other molecules. 
     
     
       6. The balloon of claim 1, 4 or 5 in which the randomized block copolymer of polyether glycol and polybutylene terephthalate is HYTREL®. 
     
     
       7. The balloon of claim 1, 4, or 5 in which the PET in the blend comprises modified PET. 
     
     
       8. The balloon of claim 7 in which the modified PET is SELAR®.